There are many olefin polymers which can be made into fibers and filaments. This includes polyethylene, polypropylene, polybutene, polypentene, and ethylene copolymerized with other olefinic monomers such as higher olefins. Olefin polymers are known for their hydrophobic properties; wettability of the polymers, including those in fibrous or filament form, is achieved by means of wetting agents provided in, or on, the polymers.
U.S. Pat. Nos. 3,847,676, 4,073,852, 4,307,143, 4,273,892, and 4,274,971 are believed to be representative of the closest prior art of which we are aware.
U.S. Pat. No. 4,189,420 discloses, inter alia, certain ethylene polymers blended with a polybutene and a mixed glyceride having at least one acyl group of 2 to 6 carbon atoms and at least one acyl group containing 8 to 22 carbon atoms.
U.S. Pat. No. 3,048,266 discloses, inter alia, an anti-fog agent of polyethylene oxide derivative in a polyolefin composition.
U.S. Pat. No. 3,048,263 discloses, inter alia, a polyolefin anti-fog agent comprising an monoglyceride of a fatty acid.
U.S. Pat. No. 2,462,331 discloses, inter alia, the incorporation into polyethylene of polyhydric alcohol esters of metal salts of either saturated or unsaturated monocarboxylic fatty acids.
Convenient references relating to fibers and filaments, including those of man-made thermoplastics, and incorporated herein by reference, are, for example:
(a) Encyclopedia of Polymer Science and Technology, Interscience, New York, Vol. 6 (1967) pp 505-555 and Vol. 9 (1968) pp 403-440; PA1 (b) Man-Made Fiber and Textile Dictionary, published by Celanese Corporation; PA1 (c) Fundamentals of Fibre Formation--The Science of Fibre Spinning and Drawing, by Andrzij Ziabicki published by John Wiley & Sons, London/New York, 1976; PA1 (d) Man-Made Fibres, by R. W. Moncrieff, published by John Wiley & Sons, London/New York, 1975; PA1 (e) Kirk-Othmer Encyclopedia of Chemical Technology, Vol. 16 for "Olefin Fibers", published by John Wiley & Sons, New York, 1981, 3rd Edition. PA1 A "monofilament" (a.k.a. monofil) refers to an extruded individual strand of denier greater than 15, usually greater than 30; PA1 A "fine denier fiber of filament" refers to an extruded strand of denier less than about 15; PA1 A "multi-filament" (a.k.a. multifil) refers to simultaneously extruded fine denier filaments formed as a bundle of fibers, generally containing at least 3, preferably at least about 15-100 fibers and can be several hundred or several thousand; PA1 "Staple fibers" refer to fine denier strands which have been formed at, or cut to, staple lengths of generally about 1 to about 8 inches; PA1 An "extruded strand" refers to an extrudate formed by passing polymer through a forming-orifice, such as a die. PA1 (a) an alkoxylated alkyl phenol along with a mixing mono-, di-, and/or triglyceride; PA1 (b) an alkoxylated alkyl phenol along with a polyoxyalkylene fatty acid ester; PA1 (c) a polyoxyalkylene fatty acid ester along with a mixed mono-, di- and/or triglyceride; or PA1 (d) an alkoxylated alkyl phenol along with a mixed mono-, di-, and/or triglyceride and with a polyoxyalkylene fatty acid ester.
In conformity with commonly accepted vernacular or jargon of the fiber and filament industry, the following definitions apply to the terms used in this disclosure:
Whereas it is known that virtually any thermoplastic polymer can be extruded as a coarse strand or monofilament, many of these, such as polyethylene and some ethylene copolymers, have not generally been found to be suitable for the making of fine denier fibers or multi-filaments. Practitioners are aware that it is easier to make a coarse monofilament yarn of 15 denier than to make a multi-filament yarn of 15 denier. It is also recognized that the mechanical and thermal conditions experienced by a bundle of filaments, whether in spinning staple fibers or in multi-filaments yarns, are very different to those in spinning monofilaments. The fact that a given man-made polymer can be extruded as a monofilament, does not necessarily herald its use in fine denier or multi-filament extrudates.
The present invention includes, especially, fine denier fibers and multi-filaments of the LLDPE ethylene copolymers. It is believed that U.S. Pat. Nos. 4,181,762, 4,258,097, and 4,356,220 are representative of the most relevant fiber art of which we are aware. U.S. Pat. No. 4,076,698 discloses methods of producing LLDPE polymers and discloses extrusion of a monofilament.